ROBERT SIEGEL, host:
You're listening to ALL THINGS CONSIDERED from NPR News.
Tensions between Iran and the United States are on the rise over an incident in the Persian Gulf. The U.S. Navy says yesterday, small Iranian attack boats harassed three American warships in the Strait of Hormuz.
Vice Admiral KEVIN COSGRIFF (Commander, Fifth Fleet, U.S. Navy): Yesterday, the Revolutionary Guard demonstrated their capacity to act irresponsibly and, in my estimation, well out of the ordinary norms of what we would expect.
SIEGEL: That's Vice Admiral Kevin Cosgriff, commander of the U.S. Fifth Fleet in Bahrain. He says the American warships had to take evasive actions to avoid the Iranians. For its part, Tehran calls the incident normal.
NPR Pentagon correspondent Tom Bowman is with us.
And, Tom, what more can you tell us about what happened yesterday?
TOM BOWMAN: Well, Robert, Navy and Pentagon officials say that five small Iranian attack boats came and swarmed around both sides of these three American ships. This is early Sunday morning in the Persian Gulf. There was a U.S. destroyer, a cruiser and a frigate, and they were heading into the Gulf on a routine patrol. The Americans say they were at least 15 miles from Iran, so outside the 12-mile territorial waters. And the Navy says the Iranian boats did not heed American radio calls, they were aggressive, moving fast, and closing to as close as several hundred yards from the American vessels.
And this is interesting, they also threw boxes into the water, but the Americans say it was unknown what was in them. Also, the Americans received a radio message, and here's what Admiral Cosgriff had to say about that.
Vice Admiral COSGRIFF: Our ships received a radio call that was threatening in nature to the effect that they were closing our ships and that the ships might - the ships would explode - the U.S. ships would explode.
BOWMAN: Now, the Navy says it's not certain that radio message came from the Iranian boats, but officials here say it's likely. And we're told that one of the American Navy ship commanders was close to firing at the Iranians, but Admiral Cosgriff, when I asked him about that, he would not confirm that.
SIEGEL: Tom, how unusual is an incident like this? Very rare or have the Iranians done things like this before?
BOWMAN: Well, you know, they have. The Navy officials say they routinely encounter Iranian Navy and also Revolutionary Guard ships in the Gulf and even some that very morning. They often exchange radio messages, so the Iranians, you know, they shadow the American ships in the Gulf. But most officials say nothing like this - nothing this threatening has happened between the two countries before.
SIEGEL: What did - yeah, go ahead, Tom.
BOWMAN: And, of course, there was an incident back in March with the British Navy and the Iranian Revolutionary Guards. This took place in the Northern Gulf, and 15 British sailors from the HMS Cornwall were in a small patrol craft. They were seized by the Revolutionary Guard in a larger boat; they were held for two weeks. At that time, the Iranians say the British intruded on their territorial waters; Britain denied this.
SIEGEL: Well, in this incident from yesterday, what's the Navy's sense of what the Iranians were up to, why they were doing it?
BOWMAN: Well, they really don't know at this point. There's speculation that the Iranians might have been probing to determine the American defensive measures, maybe trying to keep them off guard, provoking them perhaps into firing, but at this point, it's really only speculation.
SIEGEL: And is the Navy going to change any procedures as a result of this?
BOWMAN: We don't get sense of that. The admiral said that the American sailors were disciplined, measured in their response, and clearly ready to defend their ships. He wouldn't say if there were any change in procedures.
SIEGEL: Okay. Thank you, Tom.
BOWMAN: You're welcome.
SIEGEL: That's NPR's Tom Bowman at the Pentagon.